THE DISTRIBUTION OF THERMOCLINE AND MIDDLE COLD WATER IN THE BERING SEA IN SUMMER

This paper mainly deals with the distribution of thermocline and middle cold water and preliminary analyses the formation of them in the Aleutian Basin of the Bering Sea in summer.The results indicate that: (1) The water column (0~500m) can be roughly divided into four layers, i. e., the upper homogeneous layer, the thermocline, the middle cold water and the lower homogeneous layer. (2)The thermocline is approximately observed between 25m and 50m depth and it ranges from 0. 10 to 0. 16℃/m in strength.There is the thermocline in most of surveyed area and it is the largest in the southeastern part of the high seas, with more than 0. 15℃/m in strength. (3) The upper limit depth, the lower limit depth and the thickness of middle cold water ranges from 40 to 130m depth, from 150 to 260m depth and from 40 to 220 meters, respectively.The thickness of the middle cold water exceeds 100 meters in the high seas, The water temperature in the inner of the middle cold water is 1~3℃ or so. (4) The combined effects of convective and turbulent mixing is the main cause of formation of thermocline and middle cold water.